docs/api.md

   1 # [API](https://poolifier.github.io/poolifier/)
   2
   3 ## Table of contents
   4
   5 - [Pool](#pool)
   6   - [`pool = new FixedThreadPool/FixedClusterPool(numberOfThreads/numberOfWorkers, filePath, opts)`](#pool--new-fixedthreadpoolfixedclusterpoolnumberofthreadsnumberofworkers-filepath-opts)
   7   - [`pool = new DynamicThreadPool/DynamicClusterPool(min, max, filePath, opts)`](#pool--new-dynamicthreadpooldynamicclusterpoolmin-max-filepath-opts)
   8   - [`pool.execute(data, name)`](#poolexecutedata-name)
   9   - [`pool.destroy()`](#pooldestroy)
  10   - [`PoolOptions`](#pooloptions)
  11     - [``ThreadPoolOptions extends PoolOptions`](#threadpooloptions-extends-pooloptions)
  12     - [`ClusterPoolOptions extends PoolOptions`](#clusterpooloptions-extends-pooloptions)
  13 - [Worker](#worker)
  14   - [`class YourWorker extends ThreadWorker/ClusterWorker`](#class-yourworker-extends-threadworkerclusterworker)
  15
  16 ## Pool
  17
  18 ### `pool = new FixedThreadPool/FixedClusterPool(numberOfThreads/numberOfWorkers, filePath, opts)`
  19
  20 `numberOfThreads/numberOfWorkers` (mandatory) Number of workers for this pool
  21 `filePath` (mandatory) Path to a file with a worker implementation
  22 `opts` (optional) An object with the pool options properties described below
  23
  24 ### `pool = new DynamicThreadPool/DynamicClusterPool(min, max, filePath, opts)`
  25
  26 `min` (mandatory) Same as _FixedThreadPool_/_FixedClusterPool_ numberOfThreads/numberOfWorkers, this number of workers will be always active
  27 `max` (mandatory) Max number of workers that this pool can contain, the new created workers will die after a threshold (default is 1 minute, you can override it in your worker implementation).
  28 `filePath` (mandatory) Path to a file with a worker implementation
  29 `opts` (optional) An object with the pool options properties described below
  30
  31 ### `pool.execute(data, name)`
  32
  33 `data` (optional) An object that you want to pass to your worker implementation
  34 `name` (optional) A string with the task function name that you want to execute on the worker. Default: `'default'`
  35
  36 This method is available on both pool implementations and returns a promise with the task function execution response.
  37
  38 ### `pool.destroy()`
  39
  40 This method is available on both pool implementations and will call the terminate method on each worker.
  41
  42 ### `PoolOptions`
  43
  44 An object with these properties:
  45
  46 - `messageHandler` (optional) - A function that will listen for message event on each worker
  47 - `errorHandler` (optional) - A function that will listen for error event on each worker
  48 - `onlineHandler` (optional) - A function that will listen for online event on each worker
  49 - `exitHandler` (optional) - A function that will listen for exit event on each worker
  50 - `workerChoiceStrategy` (optional) - The worker choice strategy to use in this pool:
  51
  52   - `WorkerChoiceStrategies.ROUND_ROBIN`: Submit tasks to worker in a round robin fashion
  53   - `WorkerChoiceStrategies.LEAST_USED`: Submit tasks to the worker with the minimum number of executed, executing and queued tasks
  54   - `WorkerChoiceStrategies.LEAST_BUSY`: Submit tasks to the worker with the minimum tasks total execution and wait time
  55   - `WorkerChoiceStrategies.LEAST_ELU`: Submit tasks to the worker with the minimum event loop utilization (ELU) (experimental)
  56   - `WorkerChoiceStrategies.WEIGHTED_ROUND_ROBIN`: Submit tasks to worker by using a [weighted round robin scheduling algorithm](./src/pools/selection-strategies/README.md#weighted-round-robin) based on tasks execution time
  57   - `WorkerChoiceStrategies.INTERLEAVED_WEIGHTED_ROUND_ROBIN`: Submit tasks to worker by using an [interleaved weighted round robin scheduling algorithm](./src/pools/selection-strategies/README.md#interleaved-weighted-round-robin) based on tasks execution time (experimental)
  58   - `WorkerChoiceStrategies.FAIR_SHARE`: Submit tasks to worker by using a [fair share scheduling algorithm](./src/pools/selection-strategies/README.md#fair-share) based on tasks execution time (the default) or ELU active time
  59
  60   `WorkerChoiceStrategies.WEIGHTED_ROUND_ROBIN`, `WorkerChoiceStrategies.INTERLEAVED_WEIGHTED_ROUND_ROBIN` and `WorkerChoiceStrategies.FAIR_SHARE` strategies are targeted to heavy and long tasks.
  61   Default: `WorkerChoiceStrategies.ROUND_ROBIN`
  62
  63 - `workerChoiceStrategyOptions` (optional) - The worker choice strategy options object to use in this pool.
  64   Properties:
  65
  66   - `measurement` (optional) - The measurement to use in worker choice strategies: `runTime`, `waitTime` or `elu`.
  67   - `runTime` (optional) - Use the tasks [median](./src/pools/selection-strategies/README.md#median) runtime instead of the tasks average runtime in worker choice strategies.
  68   - `waitTime` (optional) - Use the tasks [median](./src/pools/selection-strategies/README.md#median) wait time instead of the tasks average wait time in worker choice strategies.
  69   - `elu` (optional) - Use the tasks [median](./src/pools/selection-strategies/README.md#median) ELU instead of the tasks average ELU in worker choice strategies.
  70   - `weights` (optional) - The worker weights to use in weighted round robin worker choice strategies: `{ 0: 200, 1: 300, ..., n: 100 }`.
  71
  72   Default: `{ runTime: { median: false }, waitTime: { median: false }, elu: { median: false } }`
  73
  74 - `restartWorkerOnError` (optional) - Restart worker on uncaught error in this pool.
  75   Default: `true`
  76 - `enableEvents` (optional) - Events emission enablement in this pool.
  77   Default: `true`
  78 - `enableTasksQueue` (optional) - Tasks queue per worker enablement in this pool.
  79   Default: `false`
  80
  81 - `tasksQueueOptions` (optional) - The worker tasks queue options object to use in this pool.
  82   Properties:
  83
  84   - `concurrency` (optional) - The maximum number of tasks that can be executed concurrently on a worker.
  85
  86   Default: `{ concurrency: 1 }`
  87
  88 #### `ThreadPoolOptions extends PoolOptions`
  89
  90 - `workerOptions` (optional) - An object with the worker options to pass to worker. See [worker_threads](https://nodejs.org/api/worker_threads.html#worker_threads_new_worker_filename_options) for more details.
  91
  92 #### `ClusterPoolOptions extends PoolOptions`
  93
  94 - `env` (optional) - An object with the environment variables to pass to worker. See [cluster](https://nodejs.org/api/cluster.html#cluster_cluster_fork_env) for more details.
  95
  96 - `settings` (optional) - An object with the cluster settings. See [cluster](https://nodejs.org/api/cluster.html#cluster_cluster_settings) for more details.
  97
  98 ## Worker
  99
 100 ### `class YourWorker extends ThreadWorker/ClusterWorker`
 101
 102 `taskFunctions` (mandatory) The task function or task functions object `{ name_1: fn_1, ..., name_n: fn_n }` that you want to execute on the worker
 103 `opts` (optional) An object with these properties:
 104
 105 - `maxInactiveTime` (optional) - Maximum waiting time in milliseconds for tasks on newly created workers. After this time newly created workers will die.
 106   The last active time of your worker will be updated when it terminates a task.
 107   If `killBehavior` is set to `KillBehaviors.HARD` this value represents also the timeout for the tasks that you submit to the pool, when this timeout expires your tasks is interrupted before completion and removed. The worker is killed if is not part of the minimum size of the pool.
 108   If `killBehavior` is set to `KillBehaviors.SOFT` your tasks have no timeout and your workers will not be terminated until your task is completed.
 109   Default: `60000`
 110
 111 - `killBehavior` (optional) - Dictates if your worker will be deleted in case a task is active on it.
 112   **KillBehaviors.SOFT**: If `currentTime - lastActiveTime` is greater than `maxInactiveTime` but a task is still executing or queued, then the worker **won't** be deleted.
 113   **KillBehaviors.HARD**: If `currentTime - lastActiveTime` is greater than `maxInactiveTime` but a task is still executing or queued, then the worker will be deleted.
 114   This option only apply to the newly created workers.
 115   Default: `KillBehaviors.SOFT`
 116
 117 #### `YourWorker.hasTaskFunction(name)`
 118
 119 `name` (mandatory) The task function name
 120
 121 This method is available on both worker implementations and returns a boolean.
 122
 123 #### `YourWorker.addTaskFunction(name, fn)`
 124
 125 `name` (mandatory) The task function name
 126 `fn` (mandatory) The task function
 127
 128 This method is available on both worker implementations and returns a boolean.
 129
 130 #### `YourWorker.removeTaskFunction(name)`
 131
 132 `name` (mandatory) The task function name
 133
 134 This method is available on both worker implementations and returns a boolean.
 135
 136 #### `YourWorker.listTaskFunctions()`
 137
 138 This method is available on both worker implementations and returns an array of the task function names.
 139
 140 #### `YourWorker.setDefaultTaskFunction(name)`
 141
 142 `name` (mandatory) The task function name
 143
 144 This method is available on both worker implementations and returns a boolean.